In a conventional electric vehicle, a prime mover such as a diesel engine, is used to drive an electric generator or alternator which supplies electric current to a plurality of electric motors. The electric motors typically are coupled to wheel sets, in line, on the vehicle. The vehicles that utilize this type of hybrid electric motors are typically railroad locomotives.
The prime mover drives the generator/alternator that typically produces an AC current that is then fully rectified with resulting DC current and voltage being distributed to current converters coupled to the traction motors. Such systems are highly integrated with each of the components typically designed and manufactured to operate with the other components in the overall system. In other words, “off the shelf” components are not readily adaptable for use in the initial design or ongoing maintenance of such vehicles. Further, such vehicles have multiple components associated with the change of AC to DC to AC power. Maintenance of such systems is expensive since specific components must be used.
In the use of hybrid drives for such vehicles, it is often necessary to add support systems that require a source of power to operate. Typically, these systems are centrally mounted on the vehicle and require the routing of specialized, pressurized, conduits to specific points around the vehicle. Conventional sources of auxiliary power are typically an internal combustion engine operated generator or a motor generator set. Such additional components and equipment add cost to the vehicle and take up space on the vehicle.
Thus there is a need for a power take-off for a vehicle that does not require an additional engine. There is a further need for a method to provide power to an auxiliary apparatus mounted on a vehicle utilizing the traction motor of the vehicle.